


Poly-tron

by behindtheimpala



Category: Voltron: Legendary Defender
Genre: Alpha Shiro (Voltron), Daddy Kink, F/F, Galra Keith (Voltron), Hurt/Comfort, Loss of Virginity, M/M, Omega Keith (Voltron), Omega Lance (Voltron), Omegaverse, PWP, Rut Fic, Virgin Shiro, daddy - Freeform, galra - Freeform, heat - Freeform, only references of pallura
Language: English
Status: Completed
Published: 2017-04-25
Updated: 2018-02-17
Packaged: 2018-10-23 17:41:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 4,200
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10724109
Author URL: https://archiveofourown.org/users/behindtheimpala/pseuds/behindtheimpala
Summary: Shiro goes into rut not realizing it, Keith and Lance help him sort things out. Alpha!Top!Shiro, Omega!Bottom!Keith, and Omega!Verse!Lance. As their heat fades, they realize that they are very compatible. When Keith goes into heat without realizing it, Shiro and Lance help him sort things out. Happy ending





	1. Chapter 1

The first person to notice was Lance, who watched Allura force Shiro aside when he got too aggressive to the alien race that they were trying to help. Lance watched Shiro pace back and forth in the dining hall, as he observed he noticed his stomach was growling even though he had had a snack just a few hours ago and he was very agitated. Lance looked over at Keith, the only other omega on their team. Keith returned his look and shrugged, not knowing what was going on with Shiro.

Lance noticed the look of an alpha in rut, but didn’t really know what it was since he had seen the look on a few others faces in the Garrison but chalked it up to being sick or something. Hunk noticed Shiro’s grumpy mood and took his plate and slowly walked out of the room, taking an extra portion for Pidge who was currently working on a second Rover.

“Shiro are you okay?” Lance said softly.

“I’m fine!” Shiro shouted, sitting down with a huff, crossing his arms. “I’m just hungry.”

Lance nodded softly. He stood up and walked over to Shiro, feeling a little attracted to him. He glanced over at Keith, who soon stood and walked over to Shiro as well. They stood on either side of Shiro, looking down at him.

“What?” He said, letting out a very aggressive and not-very-Shiro-like grunt.

“What’s your secondary sex?” Lance asked him seriously.

“That’s none of your business!” Shiro said, looking up at Lance.

Lance looked from Shiro to Keith. Keith looked down at Shiro. “Lance and I are omegas, Shiro. We can smell your rut.” Keith whispered, his hand on his hip in his usual pose.

“I never got my secondary sex, I was kidnapped before I found out.” He said, looking up at them. “I get like this sometimes, but I masturbate a few times and it kinda goes away for a few weeks.” He said, feeling ashamed that his teammates knew more than him for once.

“You’ve never wanted something like this?” Lance whispered, twisting his hip and smacking his ass. Shiro let out a loud growl, but then pulled away, looking down at the table. “No that’s rude.” Lance looked up at Keith and smirked. Both omegas, under control of the rut that the scent made them want to bend over instantly for the alpha.

“If you fuck us, it will go away for three months.” Keith whispered. “My ass is already sloppy, with an alpha in rut so close to me.” Keith said, rubbing his own bum.

“Don’t you want us?” Lance whispered softly. “You can do whatever you like… Daddy.” Lance whispered. In the next moment, he didn’t realize what happened until he was bent over the table, the nutritional goo being used as some extra lube before he slammed into Lance who was sopping wet from sensing an alpha in heat nearby.

Lance cried out. “Fuck yes! Daddy breed me.” He said, holding his legs close together so that Shiro could feel his tight hole completely as he slid in and out of him.

Keith quickly undressed, pretty much running on adrenaline and rut scent at this point. He crawled up onto the table, leaning down and lapping at Lance’s lips until he realized what was going on and kissed Keith back.

Keith moved his hand to touch his ass but looked up at Shiro, still pounding into Lance, when he growled. “Don’t touch your ass. Mine.” He whispered. “I’ll fuck you soon enough.” Keith whined softly. “Yes Daddy, I’ll be a good boy.” Keith whispered, gently stroking himself.

It didn’t feel near as good as touching his ass but it still felt better than leaving himself untouched. Lance looked up and whined. Keith looked down in the response to the sound, and smiled. He started kissing Lance again, letting their tongues mingle. “Keith, I feel it.” Lance whimpered. “He’s going to knot.” He said with a little bit of fear in his eyes.

Though Lance relaxed a little bit when Shiro only grew to half size and then pulled out of him. Keith quickly moved to the edge of the table, his ass exposed and his legs up to his chest. Keith gasped out when Shiro slid his half-knot inside him. “Daddy!” Keith cried out.

Lance crawled over to Keith and started to kiss him, wanting the trio to stay quiet and away from Allura or Coran who didn’t have secondary sexes and wouldn’t understand this imposing position. Lance moaned out against Keith’s lips when Shiro’s fingers found their way to his ass and started to finger bang him harshly.

Lance squished his hands into fists, arched his back and let out a gasp. Keith switched his hands with his own cock and reached over to start touching Lance’s cock in one hand and in the other was touching himself.

Shiro pushed in deep and knotted fully, making Keith cry out against Lances’ lips. “So full.” Keith whispered, feeling Shiro fill him with his cum. Shiro blinked a few times, realizing what had happened.

“Is everyone okay?” He whispered softly, setting a hand on Keith’s chest, two of his fingers covered in Lance’s slick and nutritional goo mixed together. Keith nodded softly. “Feels good Daddy.” He whispered.

Lance looked up at Shiro. “Daddy!” Lance pouted softly. “I want knot too!” He said in as much power as he could, still horny and needy as he was.

Shiro gently collected Keith up into his arms and held him in a way that he could still walk without his cock’s knot being painful for Keith. “Come on, Lance.” Shiro whispered. Lance took Shiro’s hand gently and walked out with him. “Daddy, I want knot!” Lance said in a pouted tone.

“When my knot now goes down, Daddy promises you’ll get knot.” He whispered. Keith looked down from his perch on Shiro’s hips and nodded. “Daddy’s knot is nice, Lance. You’ll like it. So big, so much cum.” Keith whispered.

Lance stood with his mouth open for a moment, but then nodded quickly. “Daddy I want knot.” He whispered. Shiro smiled. “I said I promise you’d get knot pretty boy.” Shiro whispered as he led them to his room. The mess was left for a very confused Hunk and Coran.


	2. Chapter 2

**Summary for the Chapter:**

> Shiro learns a bit more about himself.

It had been about three weeks since Shiro had gotten his rut, and ended up pounding Lance and Keith into the dining room table, after which they had to spend the next two weeks ritually cleaning the kitchen and dining room, courtesy of Coran, who insisted that they needed to be punished whether the need was biological or not. Lance ended up getting elbowed when he made a joke about how Keith would probably like punishment.

In the three weeks since that fateful day, Keith and Lance had grown close platonically but Shiro had kept his distance out of shame. Lance was laying in Keith's lap, studying his textbook about doing military maneuvers in zero gravity. Keith was currently reading the alien version of Harry Potter, where conveniently the Whomping Willow was a giant squid named Willow. Shiro knocked quietly on the door.

Keith slid his Harry Potter under his pillow and opened his own textbook of zero gravity maneuvers. "Come in." Keith said to the door, knowing it was Shiro.

Shiro opened the door and walked inside, giving Keith a glance. “I’m not here for business.” He said softly, looking down at Keith. “Keith your textbook is upside down.” He whispered, lifting Lances legs so that he could sit on the other side of the bed, laying Lance’s feet over his lap. Lance turned bright pink, quickly resting his textbook over his crotch not realizing he loved being manhandled by the large paladin.

Keith set his text book down as well. “What’s up?” He asked.

Shiro looked down at his feet. “Ever since we had sex, I keep thinking about it when I touch myself, I can’t,” He turned bright pink. “uhm. I can’t cum without thinking about you two.” He whispered softly, looking back up to Keith who was now as pink as cotton candy.

“Are you saying that we should start dating?” Lance said, looking up at Shiro.

Shiro nodded softly. “I’d really like that. I like you two a lot.” Shiro responded, jumping a little bit when Keith leaned over and kissed him. Lance pouted. “I want kisses too!” He whispered, he swung himself into a sitting up position, moving around so that he sat on his knees opposite of Keith, stealing away Shiro’s lips from Keith.

Keith moved down and started to kiss at Shiro’s neck, leaving soft pink marks from all the kisses. Shiro panted softly. “I promised you my knot, right?” Shiro whispered, and Lance nodded quickly, opening his eyes to look at Shiro. “I could give it to you now.” He whispered.

Keith chuckled softly. “You don’t knot every time you stick your penis in an omega ass.” He said softly.

“Oh.” Shiro said softly. “Keith will you teach me more about alphas?” He said softly.

“Did you not learn anything about secondary sexes?” Lance whispered. Shiro shook his head gently. “You find out when you turn 18 right? I was shipped out two weeks before my 18th birthday.” He whispered softly, looking down at his feet.

Lance noticed the sad mood, and gently wrapped his arm around Shiro’s shoulder, and rubbed his shoulder for a moment. “It’s okay, we all don’t know things about stuff. It’s okay not to know, we can always learn more.” Lance whispered softly, and Shiro nodded quietly.

Shiro looked up at Keith. “You said I was an alpha. What does that mean?” He whispered.

Keith nodded. “On Earth, you would be pretty much top of the food chain. Alphas are leaders of most businesses, leaders, and heads of countries.” He said softly. Shiro nodded quietly. “But being an alpha doesn’t mean that’s why you lead Voltron, though. Many alphas on Earth use their status as alphas to gain these positions since alphas are very rare.

“I think Hunk is an alpha too.” Lance whispered, but then Keith shook his head. “Hunk and Pidge are both betas, meaning that they don’t have ruts like alphas do, go into heat like omegas do, and can’t reproduce like omegas.” Keith whispered.

“Does that mean you and Lance could have kids one day?” Shiro said softly. Keith nodded. “I don’t think I’ll ever want kids.” He said. “I’m open to the idea, depending on who I’m having the kids with.” Lance said softly, and Keith nodded. 

“We can only get pregnant by our fated pair, which by the reasoning that both Lance and I went into heat when we smelled you in rut, we’re fated.” Keith added. Shiro looked up quickly. “So we’re soulmates?” He said with a little bit of excitement.

“Probably.” Lance whispered. “I’m not exactly bummed out about the fact that I’m paired to two gorgeous men.” Lance whispered happily.

“About omegas,” Keith added, giving a Lance a look to shush him. “About once a month for three days, we go into heat. Lance and I have been hanging out so much that our heats have started to slowly coincide with each other.” Keith whispered.

“Oh, like women’s periods.” Shiro said quickly, making Keith chuckle. “Kinda.” He whispered. “Lance and I could get pregnant at any time, but it happens really easily during our heats. We’re both on birth control, mostly because Allura thinks that Lance is a slut.” Keith continued. Lance pouted. “I am not!” 

“Maybe a little bit.” Keith said softly, making Shiro chuckle.

“I mostly like to bottom, meaning being the one being fucked. I typically can’t orgasm without at least a finger in my ass.” Keith said.

“I’m verse.” Lance spoke up. “I can top or bottom, but since I’m an omega I really like to bottom sometimes.” He explained with a smile.

“I think I’d only like to put my dick into someone else. Having someone put their dick in me sounds bad.” Shiro said softly. Lance nodded. “That means you’re a top!” He explained. “Most alphas are tops.” He said, leaning over and kissing his cheek.

“How are we going to make this work?” Shiro whispered softly.

“We can do whatever a normal couple does, except there’s three of us.” Lance whispered with a smile, and Shiro nodded. “Does that mean we can go on dates?” Shiro asked, looking between Lance and Keith, trying to make sure they both understood that he was looking for a fully committed relationship and not some fling.

Keith and Lance nodded. “Yeah.” Keith said. “Of course.” Lance whispered.

“Do you have anything in mind?” Lance said, speaking up now.

“Allura gave me this Altean puzzle game. It’s kind of like a rubix cube…” Shiro paused, unsure of what to say.

“We could curl up in your bed with snacks and take turns trying to solve it.” Lance offered, and Keith nodded. “Of course, I’ll be the first one.” He said confidently, making both Lance and Shiro pause and then laugh. “Yeah right! I’ll be the first one to solve it.” Lance exclaimed, getting up and following Shiro back to his room.

Lance stuck his tongue out at Keith as they walked down the hallway. Shiro gently reached out and clasped their hands. Keith and Lance were slow to realize but when they realized that Shiro was trying to hold both of their hands, they both turned bright pink and quit teasing each other.

They stopped by the kitchen, getting a few dessert treats that Hunk had made a few days ago and went to curl up in Shiro’s bed, all of them making advances that they could solve this puzzle the fastest.

Lance wasn’t able to solve it, Keith was able to solve it but it took him quite a long time and Shiro impressed them all by taking only a few minutes to solve it, not revealing the fact that he had had Pidge teach him how to solve the puzzle so that he could impress Keith and Lance.

The three boys ended up falling asleep curled up together, with Shiro in the middle, on Shiro’s bed.

**Notes for the Chapter:**

> Any kudos or comments are appreciated!!


	3. Chapter 3

Lance, Shiro, and Keith had been dating long enough for the rest of the team including Allura and Coran to know that they were dating but not long enough that they had come out themselves to the rest of the team. They were all currently sitting at the large table where they would occassionally share a meal almost as if they were a family. It had been Lances idea at first, who was missing his families large Sunday evening meals. Lance was sitting next to Shiro, and Keith was sitting on the other side of Shiro. Pidge and Allura were sitting next to each other on the other side of the table, there was an empty chair where Hunk was sitting but he was in the kitchen finishing up their meal. Coran was walking around and setting plates and silverware in front of them.

Lance opened his mouth to speak, and Allura suddenly coughed and Lance shut his mouth. They sat in silence until Hunk walked inside. "Why is everyone so quiet?" Hunk said as he started serving. Lance looked around and turned bright pink and looked down.

"Wel, spit it out!" Coran said, unsure as to why everyone was being so cautious.

Allura stood up suddenly. "Pidge and I are dating." She said softly, and Pidge stood up quickly. "Yes, we are." Pidge said. Lance and Keith stared up at Pidge. Without any objection, they slowly sat down.

Shiro smiled. "Matt would be proud." He whispered softly and Pidged turned bright pink and blushed.

Shiro cleared his throat and then spoke. "Lance, Keith, and I are dating as well." He whispered softly. 

"Oh a trio relationship, how fascinating." Allura said curiously. Allura looked at Lance and Keith, who she now realized only had eyes for Shiro.

Hunk looked down at Coran. "We're the lonely bachelors now, huh?" Hunk chuckled, and Coran nodded softly. 

"I give my blessing to both relationships." Coran said with a smile. Shiro felt touched but Allura ran over and hugged Coran. "Thank you, that makes me so happy." Allura said happily and Coran nodded softly. "Your father would be so proud that you found someone to love in these trying times." Coran said softly, rubbing Allura's back gently.

Hunk served and everyone started eating, slowly the tense air dissolved into an air of happy chattering.

Lance looked over at Keith, who had stayed silent and was shaking a little bit as he tried to eat. Lance poked Shiro. "Shiro, Keith is going into heat." He whispered softly.

Shiro looked over at Keith, and suddenly smelled something sweet. "Is that why he smells so sweet?" Shiro whispered and Lance nodded quickly.

"We're going to turn in early." Shiro said quickly, and Shiro and Lance quickly dragged Keith out of the dining room. Keith let out a soft whimper when he was manhandled out of the room.

"What was that for?" He said once they were out in the hallway. "You're in heat!" Lance said quickly. "We can smell it!" Shiro whispered. 

Keith paused. "I am?" He whispered, gently reaching down to his pants and found that his bum was wet. "Whoops." He said, moving his hand away. Shiro took a sniff, and suddenly smelled it. "We don't have much time until I start fucking someone." Shiro whispered to Keith. Lance nodded quickly and they quickly moved to Shiro's room.

Halfway there, Keith's legs went out and he fell to his knees. He moaned out. "Daddy." He panted softly. Shiro ran back and quickly picked up Keith. "Daddys here, we're almost to my room." He whispered softly as Lance ran ahead to strip his clothes and lay an extra comforter over the bed so they wouldn't ruin Shiro's bed set.

Shiro came to the room, still holding Keith whose skin was now slowly turning a pastel purple.

Lance looked over and gasped. "Keith, you're purple!" He said suddenly as Shiro laid him down onto the bed.

(Continued in Chapter 4)

**Notes for the Chapter:**

> Any comments or kudos are greatly appreciated!!


	4. Chapter 4: Final

**Summary for the Chapter:**

> Lance and Shiro help Keith with heat

Keith wiggled in Lances arms, whimpering. As they walked into Shiros bedroom, Keith was able to wiggle free of Lances grip.

"Keith! You're purple!" Lance said, raising his voice clearly the only one who still had mental capabilities as he watched as Keith used his very shaky legs to make his way to Shiro.

Shiro from Lance down to Keith, pausing before reaching down and helping Keith up, sitting down on the bed and planting Keith in his lap.

_*fffft*_

Lance cocked his head as he slowly made his way to sit next to Shiro, his vision going foggy for a moment but he remained his composure. Training to be a pilot as an omega helped him have concentration during difficult times. Lance looked up at Keith to see two new appendages coming up out from the sides of his head. Keith, who was busy trying to nuzzle Shiro while Shiro kept him at semi-arms distance trying to look at him.

"Keith, you have cat ears." Shiro whispered softly.

Lance tried to take a deep breath to calm himself down, and instead got a big whiff of Shiros own pheromones that were reacting with Keiths. Lance slowly, and gently nuzzled his face into Shiros neck. "Daddy," Lance grunted out.

Shiros strength broke against Keith and he suddenly had Keiths face at his neck taking deep breaths through his nose.

"Hey, hey, we have to take this seriously." Shiro whimpered out, his Japanese raising coming out as he tried extra hard to stay composed. He grunted, his hands slowly sliding around to Keiths hips and then squeezing Keiths ass. Keith grunted loudly. "Oh god, fuck me fuck me." He whispered, his less-than-usually-nimble fingers trying to pull his clothes off, his shirt coming off with a quick yank but as he was taking a moment to take off his jeans and Lance made his way into Shiros lap, his t-shirt already on the ground next to Keiths.

Keith whined, trying to work even quicker which added to his frustration as Shiro was able to get his shirt off and Lance unzipped his pants. Lance gasped out when two cold metal fingers slowly slid into his slick hole. "Daddy!" Lance keened out, spreading his legs to accommodate Shiro a bit more.

"Ssssshiroooo," Keith whimpered, now completely naked as he crawled on the bed, kissing and sucking as Shiros neck to make little red marks.

"Keith should be in the middle today, huh?" Shiro whispered, speaking to Lance. Lance nodded quickly.

The attention on Lance quickly shifted to Keith as Shiro crawled deeper onto the bed. Lance whined when his hole suddenly wasn't getting attention. Keith gasped as Shiro pushed him down onto the bed. Lance soon followed. Shiro laid next to Keiths hip and took his hard cock into his mouth, making Keith moan out and instinctively spread his legs. Lance crawled between Keiths legs.

"Never thought I'd ever eat purple boy pussy." Lance smirked before using his tongue to make Keith dig his fingers into the sheets and cry out.

Shiro used his free hand to cover Keiths mouth, and when Keith licked him switched to using two fingers inside his mouth as a pacifier instead to keep him quiet.

Lance gently rutted into the bedsheets as he ate Keith, his smell amazing even though it was omega on omega. Shiro reached down and spanked Lance, which made him cry out into Keiths hole. He lifted his head. "Hey! I wasn't being naughty!" Lance objected.

Shiro lifted his head and through his haze saw Lance looking down at him with a face of indignation, his mouth and chin covered in purple liquid from Keith.

"God you're fucking sexy." Shiro whispered, grabbing Lances neck to pull him in for a deep kiss, and Lance definitely didn't object to that.

Keith whined. "Fuck me!!" He cried out a moment later, pulling Lance and Shiro back to their omega on their hands that was in the middle of a heat. Lance chuckled softly, gently leading Keith to join them, kissing Keith as Shiro kissed his neck, using his now warmed fingers to slowly finger Keith who was already sloppy wet so that Keith could take his cock.

Kieth whimpered, and keened out when Lance decided to try something. He reached up and very timidly started to pet Keiths fluffy cat ears as if he was actually a kitty.

Shiro looked on with curiousity, and a slight twinge of worry in his gut from his previous interactions with beings that had those purple ears. Keith whined, and then soft vibrations started coming from his chest and he nuzzled his face into the crook between Lances neck and collarbones. Shiros worry melted as he felt Keith start to purr.

"Awh, you like that big guy?" Lance whispered softly, and Keith nodded slowly.

Keith distracted by the petting, Shiro slowly lined up and slid into Keith who was maybe a twinge too tight still but that ache led to Keith gasping out and then biting down hard onto Lance. Lance cried out, his dick twitching. "Fuck that was hot." Shiro commented, staying fully seated inside Keith for a moment to help him get adjusted to the size.

Lance looked down at his collarbone to see a deep red bite mark, starting to be surrounded by red puffy skin. Lance let out a little yelp as Keith started to lap at his cock. Shiro smiled, using that quiet moment to start to thrust inside Keiths warm hole. 

Keith gasped out, pausing for a moment before Lance set a hand on the back of his neck to ground him, and Keith calmed back down enough to be able to take Lance into his mouth.

Both Lance and Shiro moaned out. Shiro upped his pace and Lance grabbed onto Keiths hair to control his movements a little bit. They moved in silence for a moment, all of them too engrossed in their own pleasure to realize the others in the situation. What brought them back to the real world, was Keith crying out and Shiro grunting as he orgasmed inside Keith and started to grow his knot.

Lance glanced up to see the pleasured look on Shiros face only to blow his load down Keiths throat. "Fuck," He whispered softly. "You okay Keith?" Lance whispered softly. 

Keith nodded in slow movements, letting himself be manhandled back so that they could lay down, all of them satisfied.

"So I guess you really are Galra..." Shiro whispered softly, grunting as another load stuffed Keith even more and came to the realization that he had forgotten to wear a condom today.

Shiro smirked to himself, watching Keith lay haphazardly on his side purring softly as Lance gently rubbed Keiths ears in his half-dazed, half-sleepy state. Shiro wrapped his arms around Keith, knowing whatever was thrown their way, he would do just fine as long as he had his boys at his side.

**Notes for the Chapter:**

> Comments and Kudos greatly appreciated!!

**Author's Note:**

> Any comments or kudos are greatly appreciated!


End file.
